Nogo expression in human immune cell subpopulations. (a) Detection of high transcript levels of Nogo-B and very low levels of Nogo-A in human T cells (CD3+), B cells (CD19+) and monocytes (CD14+) in relation to the expression in human brain (human brain is set to the value of 1.0 on the y-axis). Only T cells express low levels of Nogo-C, whereas all Nogo splicing variants are highly expressed in human brain, serving as calibrator. Data are shown as means and standard deviations of independent real-time PCR experiments using cDNAs obtained from the respective immune cell populations of four different donors. (b) and (c) Representative Western Blots for the detection of Nogo-B and Nogo-A proteins in human brain/immune cell subpopulations and attached controls for unspecific reactions of secondary antibody. The protein distribution reflects the transcript level, with Nogo-B being present in all cell types and Nogo-A only showing signals in human brain at 140 KDa (the specific target peptide rhNIG serves as positive control). Nogo-B shows either two bands at 44/45 KDa in human brain, or one band at 45 KDa in immune cell subpopulations. Although the antibody used in (b) should be able to detect Nogo-C and Nogo-A, no signals were observed. Images shown are representative for independent experiments performed using the respective immune cell subpopulations of three different donors.